Cyclic sulfonate compounds as photoacid generators in resist applications

ABSTRACT

Novel photoacid generator compounds are provided. Compositions that include the novel photoacid generator compounds are also provided. The present disclosure further provides methods of making and using the photoacid generator compounds and compositions disclosed herein. The compounds and compositions are useful as photoactive components in chemically amplified resist compositions for various microfabrication applications.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a U.S. National Phase filing of international patentapplication number PCT/US2019/022252, filed on Mar. 14, 2019 that claimspriority to U.S. provisional patent application Ser. No. 62/644,288,filed on Mar. 16, 2018, the entireties of which are incorporated hereinby reference.

TECHNICAL FIELD

The present disclosure relates to new photoacid generator compounds(“PAGs”) and compositions that comprise such PAG compounds. Inparticular, the PAG compounds of the present disclosure have excellentsolubility in organic solvents and exhibit higher sensitivity and betterperformance in a photolithographic process than conventional PAGcompounds.

BACKGROUND

Photoresists are photosensitive films for transfer of images to asubstrate. They form negative or positive images. After coating aphotoresist on a substrate, the coating is exposed through a patternedphotomask to a source of activating energy, such as ultraviolet light,to form a latent image in the photoresist coating. The photomask hasareas opaque and transparent to activating radiation that define animage desired to be transferred to the underlying substrate.

Chemical amplification-type photoresists have proven to be useful inachieving high sensitivity in processes for forming ultrafine patternsin the manufacture of semiconductors. These photoresists are prepared byblending a PAG with a polymer matrix having acid labile structures.According to the reaction mechanism of such a photoresist, the photoacidgenerator generates acid when it is irradiated by the light source, andthe main chain or branched chain of the polymer matrix in the exposed orirradiated portion reacts in a so called “post exposure bake”(PEB) withthe generated acid and is decomposed or cross-linked, so that thepolarity of the polymer is altered. This alteration of polarity resultsin a solubility difference in the developing solution between theirradiated exposed area and the unexposed area, thereby forming apositive or negative image of a mask on the substrate. Acid diffusion isimportant not only to increase photoresist sensitivity and throughput,but also to limit line edge roughness due to shot noise statistics.

In a chemically amplified photoresist, the solubility-switchingchemistry necessary for imaging is not caused directly by the exposure;rather exposure generates a stable catalytic species that promotessolubility-switching chemical reactions during the subsequent PEB step.The term “chemical amplification” arises from the fact that eachphotochemically-generated catalyst molecule can promote manysolubility-switching reaction events. The apparent quantum efficiency ofthe switching reaction is the quantum efficiency of catalyst generationmultiplied by the average catalytic chain length. The original exposuredose is “amplified” by the subsequent chain of chemical reaction events.The catalytic chain length for a catalyst can be very long (up toseveral hundred reaction events) giving dramatic exposure amplification.

Chemical amplification is advantageous in that it can greatly improveresist sensitivity, but it is not without potential drawbacks. Forinstance as a catalyst molecule moves around to the several hundredreactions sites, nothing necessarily limits it to the region that wasexposed to the imaging radiation. There is a potential trade-off betweenresist sensitivity and imaging fidelity. For example, the amplifiedphotoresist is exposed through a photomask, generating acid catalyst inthe exposed regions. The latent acid image generated in the first stepis converted into an image of soluble and insoluble regions by raisingthe temperature of the wafer in the PEB, which allows chemical reactionsto occur. Some acid migrates out of the originally exposed regioncausing “critical dimension bias” problems. After baking, the image isdeveloped with a solvent. The developed feature width may be larger thanthe nominal mask dimension as the result of acid diffusion from exposedinto the unexposed regions. For much of the history of amplified resiststhis trade-off was of little concern as the catalyst diffusion distanceswere insignificant relative to the printed feature size, but as featuresizes have decreased, the diffusion distances have remained roughly thesame and catalyst diffusion has emerged as a significant concern.

In order to generate enough acid which would change the solubility ofthe polymer, a certain exposure time is required. For a known PAGmolecule like N-Hydroxynaphthalimide triflate (“NIT”), this exposuretime is rather long (due to its low absorption at 365 nm or longer).Increasing the concentration of such PAGs, however, will not result infaster exposure times because the solubility of the PAG is the limitingfactor. Another possibility is to add sensitizers which absorb the lightand transfer energy to the PAG which would then liberate the acid. Suchsensitizers, however, must be used in rather high concentrations inorder to be able to transfer the energy to a PAG in close proximity. Atsuch high concentrations, sensitizers often have an absorption which istoo high and has negative effects on the shape of the resist profileafter development.

Higher sensitivity is also needed in any application where effects basedon a photo generation of acid is used. In addition to resistapplications these applications could be for photo-inducedpolymerization, photo-induced crosslinking, photo-induced degradation,photo-induced deprotection, photo-induced color change or photo-inducedtransformation of functional groups or any combination of at least twoof them.

Accordingly, there is a need in the art for PAGs that exhibit better asolubility, which means that more active molecules are imparted into theformulation, wherein a composition comprising these compounds has a highsensitivity towards electromagnetic radiation, in particular towardselectromagnetic radiation with a wavelength of 200 to 500 nm, and—at thesame time—allows the production of a patterned structure with a higherresolution, compared to the photoresist compositions known from theprior art.

SUMMARY

The present disclosure satisfies this need by providing sulfonic acidderivative compound represented by Formula (I):

wherein X is either H or —OH; and Y is a cation selected from eitherFormula A or B:

wherein R¹, R², and R³ are each independently selected from the groupconsisting of a vinyl group, an allyl group, optionally substituted(C₁-C₂₀)alkyl group, and an optionally substituted (C₆-C₁₅)aralkylgroup, wherein R¹ and R² may be joined together along with the sulfur towhich they are attached to form a ring; and n is an integer from 1 to10.

In some embodiments, the present disclosure also provides resistcompositions comprising imaging-effective amounts of one or more PAGaccording to the present disclosure and a resin.

In other embodiments, the present disclosure provides methods forforming relief images of the photoresists of the present disclosure,including methods for forming highly resolved patterned photoresistimages (e.g., a patterned line having essentially vertical sidewalls) ofsub-quarter micron dimensions or less, such as sub-0.2 or sub-0.1 microndimensions.

The present disclosure further provides articles of manufacturecomprising substrates such as a microelectronic wafer or a flat paneldisplay substrate having coated thereon the photoresists and reliefimages of the present disclosure. Other aspects of the presentdisclosure are disclosed infra.

DETAILED DESCRIPTION Definitions

Unless otherwise stated, the following terms used in this Application,including the specification and claims, have the definitions givenbelow. It must be noted that, as used in the specification and theappended claims, the singular forms “a,” “an,” and “the” include pluralreferents unless the context clearly dictates otherwise.

All numerical designations, such as, weight, pH, temperature, time,concentration, and molecular weight, including ranges, areapproximations which are varied by 10%. It is to be understood, althoughnot always explicitly stated, that all numerical designations arepreceded by the term “about.” It also is to be understood, although notalways explicitly stated, that the reagents described herein are merelyexemplary and that equivalents of such are known in the art.

In reference to the present disclosure, the technical and scientificterms used in the descriptions herein will have the meanings commonlyunderstood by one of ordinary skill in the art, unless specificallydefined otherwise. Accordingly, the following terms are intended to havethe following meanings.

As used herein, the term “moiety” refers to a specific segment orfunctional group of a molecule. Chemical moieties are often recognizedchemical entities embedded in or appended to a molecule.

As used herein the term “aliphatic” encompasses the terms alkyl,alkenyl, alkynyl, each of which being optionally substituted as setforth below.

As used herein, an “alkyl” group refers to a saturated aliphatichydrocarbon group containing from 1-20 (e.g., 2-18, 3-18, 1-8, 1-6, 1-4,or 1-3) carbon atoms. An alkyl group can be straight, branched, cyclicor any combination thereof. Examples of alkyl groups include, but arenot limited to, methyl, ethyl, propyl, isopropyl, butyl, isobutyl,sec-butyl, tert-butyl, n-pentyl, n-heptyl, or 2-ethylhexyl. An alkylgroup can be substituted (i.e., optionally substituted) with one or moresubstituents or can be multicyclic as set forth below.

Unless specifically limited otherwise, the term “alkyl,” as well asderivative terms such as “alkoxy” and “thioalkyl,” as used herein,include within their scope, straight chain, branched chain and cyclicmoieties.

As used herein, an “alkenyl” group refers to an aliphatic carbon groupthat contains from 2-20 (e.g., 2-18, 2-8, 2-6, or 2-4) carbon atoms andat least one double bond. Like an alkyl group, an alkenyl group can bestraight, branched or cyclic or any combination thereof. Examples of analkenyl group include, but are not limited to, allyl, isoprenyl,2-butenyl, and 2-hexenyl. An alkenyl group can be optionally substitutedwith one or more substituents as set forth below.

As used herein, an “alkynyl” group refers to an aliphatic carbon groupthat contains from 2-20 (e.g., 2-8, 2-6, or 2-4) carbon atoms and has atleast one triple bond. An alkynyl group can be straight, branched orcyclic or any combination thereof. Examples of an alkynyl group include,but are not limited to, propargyl and butynyl. An alkynyl group can beoptionally substituted with one or more substituents as set forth below.

As used herein, the term “alicyclic” refers to an aliphatic ringcompound or group comprising at least three carbon atoms and the bondsbetween pairs of adjacent atoms may all be of the type designated singlebonds (involving two electrons), or some of them may be double or triplebonds (with four or six electrons, respectively).

A “halogen” is an atom of the 17th Group of the period table, whichincludes fluorine, chlorine, bromine and iodine.

As used herein, an “aryl” group used alone or as part of a larger moietyas in “aralkyl,” “aralkoxy,” or “aryloxyalkyl” refers to monocyclic(e.g., phenyl); bicyclic (e.g., indenyl, naphthalenyl,tetrahydronaphthyl, tetrahydroindenyl); and tricyclic (e.g., fluorenyltetrahydrofluorenyl, or tetrahydroanthracenyl, anthracenyl) ring systemsin which the monocyclic ring system is aromatic or at least one of therings in a bicyclic or tricyclic ring system is aromatic. The bicyclicand tricyclic groups include benzofused 2-3 membered carbocyclic rings.For example, a benzofused group includes phenyl fused with two or moreC₄₋₈ carbocyclic moieties. An aryl is optionally substituted with one ormore substituents as set forth below.

As used herein, an “aralkyl” or “arylalkyl” group refers to an alkylgroup (e.g., a C₁₋₄ alkyl group) that is substituted with an aryl group.Both “alkyl” and “aryl” have been defined above. An example of anaralkyl group is benzyl. An aralkyl is optionally substituted with oneor more substituents as set forth below.

As used herein, a “cycloalkyl” group refers to a saturated carbocyclicmono- or bicyclic (fused or bridged) ring of 3-10 (e.g., 5-10) carbonatoms. Examples of cycloalkyl groups include cyclopropyl, cyclobutyl,cyclopentyl, cyclohexyl, cycloheptyl, adamantyl, norbornyl, cubyl,octahydro-indenyl, decahydro-naphthyl, bicyclo[3.2.1]octyl,bicyclo[2.2.2]octyl, bicyclo[3.3.1]nonyl, bicyclo[3.3.2]decyl,bicyclo[2.2.2]octyl, adamantyl, azacycloalkyl, or((aminocarbonyl)cycloalkyl)cycloalkyl.

As used herein, the term “heteroaryl” group refers to a monocyclic,bicyclic, or tricyclic ring system having 4 to 18 ring atoms wherein oneor more of the ring atoms is a heteroatom (e.g., N, O, S, orcombinations thereof) and in which the monocyclic ring system isaromatic or at least one of the rings in the bicyclic or tricyclic ringsystems is aromatic. A heteroaryl group includes a benzofused ringsystem having 2 to 3 rings. For example, a benzofused group includesbenzo fused with one or two 4 to 8 membered heterocycloaliphaticmoieties (e.g., indolizyl, indolyl, isoindolyl, 3H-indolyl, indolinyl,benzo[b]furyl, benzo[b]thiophenyl, quinolinyl, or isoquinolinyl). Someexamples of heteroaryl are azetidinyl, pyridyl, 1H-indazolyl, furyl,pyrrolyl, thienyl, thiazolyl, oxazolyl, imidazolyl, tetrazolyl,benzofuryl, isoquinolinyl, benzthiazolyl, xanthene, thioxanthene,phenothiazine, dihydroindole, benzo[1,3]dioxole, benzo[b]furyl,benzo[b]thiophenyl, indazolyl, benzimidazolyl, benzthiazolyl, puryl,cinnolyl, quinolyl, quinazolyl, cinnolyl, phthalazyl, quinazolyl,quinoxalyl, isoquinolyl, 4H-quinolizyl, benzo-1,2,5-thiadiazolyl, or1,8-naphthyridyl.

Without limitation, monocyclic heteroaryls include furyl, thiophenyl,2H-pyrrolyl, pyrrolyl, oxazolyl, thazolyl, imidazolyl, pyrazolyl,isoxazolyl, isothiazolyl, 1,30,4-thiadiazolyl, 2H-pyranyl, 4-H-pranyl,pyridyl, pyridazyl, pyrimidyl, pyrazolyl, pyrazyl, or 1,3,5-triazyl.Monocyclic heteroaryls are numbered according to standard chemicalnomenclature.

Without limitation, bicyclic heteroaryls include indolizyl, indolyl,isoindolyl, 3H-indolyl, indolinyl, benzo[b]furyl, benzo[b]thiophenyl,quinolinyl, isoquinolinyl, indolizyl, isoindolyl, indolyl,benzo[b]furyl, bexo[b]thiophenyl, indazolyl, benzimidazyl,benzthiazolyl, purinyl, 4H-quinolizyl, quinolyl, isoquinolyl, cinnolyl,phthalazyl, quinazolyl, quinoxalyl, 1,8-naphthyridyl, or pteridyl.Bicyclic heteroaryls are numbered according to standard chemicalnomenclature.

A heteroaryl is optionally substituted with one or more substituents asis set forth below.

A “heteroarylalkyl” group, as used herein, refers to an alkyl group(e.g., a C₁₋₄ alkyl group) that is substituted with a heteroaryl group.Both “alkyl” and “heteroaryl” have been defined above. A heteroarylalkylis optionally substituted with one or more substituents as is set forthbelow.

As used herein, an “acyl” group refers to a formyl group or R^(X)—C(O)—(such as -alkyl-C(O)—, also referred to as “alkylcarbonyl”) where“alkyl” have been defined previously.

As used herein, the term “acyloxy” includes straight-chain acyloxy,branched-chain acyloxy, cycloacyloxy, cyclic acyloxy,heteroatom-unsubstituted acyloxy, heteroatom-substituted acyloxy,heteroatom-unsubstituted C_(n)-acyloxy, heteroatom-substitutedC_(n)-acyloxy, alkylcarbonyloxy, arylcarbonyloxy, alkoxycarbonyloxy,aryloxycarbonyloxy, and carboxylate groups.

As used herein, an “alkoxy” group refers to an alkyl-O— group where“alkyl” has been defined previously.

As used herein, a “carboxy” group refers to —COOH, —COOR^(X), —OC(O)H,—OC(O)R^(X) when used as a terminal group; or —OC(O)— or —C(O)O— whenused as an internal group.

As used herein, “Alkoxycarbonyl” means —COOR where R is alkyl as definedabove, e.g., methoxycarbonyl, ethoxycarbonyl, and the like.

As used herein, a “sulfonyl” group refers to —S(O)₂—R^(x) when usedterminally and —S(O)₂— when used internally.

The term “alkylthio” includes straight-chain alkylthio, branched-chainalkylthio, cycloalkylthio, cyclic alkylthio, heteroatom-unsubstitutedalkylthio, heteroatom-substituted alkylthio, heteroatom-unsubstitutedC_(n)-alkylthio, and heteroatom-substituted C_(n)-alkylthio. In certainembodiments, lower alkylthios are contemplated.

As used herein, the term “amine” or “amino” includes compounds where anitrogen atom is covalently bonded to at least one carbon or heteroatom.The term “amine” or “amino” also includes —NH₂ and also includessubstituted moieties. The term includes “alkyl amino” which comprisesgroups and compounds wherein the nitrogen is bound to at least oneadditional alkyl group. The term includes “dialkyl amino” groups whereinthe nitrogen atom is bound to at least two additional independentlyselected alkyl groups. The term includes “arylamino” and “diarylamino”groups wherein the nitrogen is bound to at least one or twoindependently selected aryl groups, respectively.

The term “haloalkyl” refers to alkyl groups substituted with from one upto the maximum possible number of halogen atoms. The terms “haloalkoxy”and “halothioalkyl” refer to alkoxy and thioalkyl groups substitutedwith from one up to five halogen atoms.

The phrase “optionally substituted” is used interchangeably with thephrase “substituted or unsubstituted.” As described herein, compounds ofthe present disclosure can optionally be substituted with one or moresubstituents, such as are illustrated generally above, or as exemplifiedby particular classes, subclasses, and species of the presentdisclosure. As described herein any of the above moieties or thoseintroduced below can be optionally substituted with one or moresubstituents described herein. Each substituent of a specific group isfurther optionally substituted with one to three of halo, cyano,oxoalkoxy, hydroxy, amino, nitro, aryl, haloalkyl, and alkyl. Forinstance, an alkyl group can be substituted with alkylsulfanyl and thealkylsulfanyl can be optionally substituted with one to three of halo,cyano, oxoalkoxy, hydroxy, amino, nitro, aryl, haloalkyl, and alkyl.

In general, the term “substituted,” whether preceded by the term“optionally” or not, refers to the replacement of hydrogen radicals in agiven structure with the radical of a specified substituent. Specificsubstituents are described above in the definitions and below in thedescription of compounds and examples thereof. Unless otherwiseindicated, an optionally substituted group can have a substituent ateach substitutable position of the group, and when more than oneposition in any given structure can be substituted with more than onesubstituent selected from a specified group, the substituent can beeither the same or different at every position. A ring substituent, suchas a heterocycloalkyl, can be bound to another ring, such as acycloalkyl, to form a spiro-bicyclic ring system, e.g., both rings shareone common atom. As one of ordinary skill in the art will recognize,combinations of substituents envisioned by this present disclosure arethose combinations that result in the formation of stable or chemicallyfeasible compounds.

Although the drawings show only one isomer with respect to theconstitution at the double bond this does not mean that only this isomeris meant but rather displays one isomer as representative for allisomers. Hence the cis- as well as the trans-isomers as well as mixturesof the two are included in the general description of the compounds andstructures.

Modifications or derivatives of the compounds disclosed throughout thisspecification are contemplated as being useful with the methods andcompositions of the present disclosure. Derivatives may be prepared andthe properties of such derivatives may be assayed for their desiredproperties by any method known to those of skill in the art. In certainaspects, “derivative” refers to a chemically modified compound thatstill retains the desired effects of the compound prior to the chemicalmodification.

Sulfonic Acid Derivate Photoacid Generator Compounds

The sulfonic acid derivative compounds according to the presentdisclosure can be used as photoacid generators as will be explained inmore detail below. Surprisingly, it has been discovered that PAGcompounds of the present disclosure are characterized by excellentsolubility and photoreactivity towards electromagnetic radiation, inparticular towards electromagnetic radiation with a wavelength in therange from 150 to 500 nm, preferably in the range from 300 to 450 nm,more preferably in the range from 350 to 440 nm, more preferably atwavelengths of 365 nm (i-line), 405 (h-line) and 436 nm (g-line).

The sulfonic acid derivative compounds according to the presentdisclosure are N-hydroxynaphthalimide sulfonate derivatives representedby Formula (I):

wherein X is either H or —OH; and Y is a cation selected from eitherFormula A or B:

wherein R¹, R², and R³ are each independently selected from the groupconsisting of a vinyl group, an allyl group, optionally substituted(C₁-C₂₀)alkyl group, and an optionally substituted (C₆-C₁₅)aralkylgroup, wherein R¹ and R² may be joined together along with the sulfur towhich they are attached to form a ring; and n is an integer from 1 to10.

In some embodiments, R¹, R², and R³ in Formula (I)(A) is an optionallysubstituted (C₆-C₁₅)aralkyl group. Examples of such PAG compoundsinclude those in Table 1:

TABLE 1

A-1 X = H

A-2 X = H

A-4 X = H

A-5 X = OH

A-6 X = OH

A-8 X = OH

A-11 X = H

A-12 X = H

In other embodiments R¹ and R² in Formula (I)(A) are joined togetheralong with the sulfur to which they are attached to form a ring and R³is an optionally substituted (C₆-C₁₅)aralkyl group. Examples of such PAGcompounds include those in Table 2:

TABLE 2

A-3 X = H

A-7 X = OH

In other embodiments R¹ and R² in Formula (I)(B) are each an optionallysubstituted (C₆-C₁₅)aralkyl group. Examples of such PAG compoundsinclude those in Table 3:

TABLE 3

A-9 X = H

A-10 X = OH

A-13 X = H

A-14 X = OH

PAGs according to the present disclosure impart a high degree ofefficiency to the photolithography process and leads to enhancedcontrast and resolution between exposed and unexposed regions of theresist composition. The amount of PAG and the energy supplied by the UVirradiation are chosen such that they are sufficient to allow thedesired polycondensation.

Compounds of the present disclosure generate acids upon irradiatingwith, for example, an ArF excimer laser. Compounds of the presentdisclosure also exhibit high solubility in organic solvents such asPGMEA. Table 4 shows the solubility of a sample of the compoundsdisclosed herein in a PGMEA solvent.

TABLE 4 Property A-1 A-2 A-3 A-4 Solubility (wt %) >50% 29% 71% >50%PGMEA

PAGs of the present disclosure may be suitably used in positive-actingor negative-acting chemically amplified photoresists, i.e.,negative-acting resist compositions which undergo a photoacid-promotedcross-linking reaction to render exposed regions of a coating layer ofthe resist less developer soluble than unexposed regions, andpositive-acting resist compositions which undergo a photoacid-promoteddeprotection reaction of acid labile groups of one or more compositioncomponents to render exposed regions of a coating layer of the resistmore soluble in an aqueous developer than unexposed regions.

Preferred imaging wavelengths for photoresists of the present disclosureinclude sub-300 nm wavelengths, e.g., 248 nm, and sub-200 nmwavelengths, e.g., 193 nm and EUV, more preferably in the range from 200to 500 nm, preferably in the range from 300 to 450 nm, even morepreferably in the range from 350 to 440 nm, most preferably atwavelengths of 365 nm (i-line), 405 (h-line) and 436 nm (g-line).

Synthesis of Compounds

There is no particular limitation for the method for synthesizing theadamantane-containing sulfonate compounds disclosed herein, and anywell-known approach can be used for the synthesis of these compounds.The synthesis of compound A1 was shown in Scheme 1.

Compositions

Compositions of the present disclosure comprise (i) at least onephotoacid generator of Formula (I); (ii) at least one compound which iscapable of being imparted with an altered solubility in an aqueoussolution in the presence of an acid; (iii) an organic solvent; and,optionally, (iv) an additive.

Compositions according to the present disclosure comprising thephotoacid generators of Formula (I) are suitable for use as aphotoresist in a variety of applications, in particular for theproduction of electronic devices, including flat panel display (in thiscase the photoresist can be coated glass substrate or a layer of indiumtin oxide) and a semiconductor device (in this case the photoresist canbe coated onto a silicon wafer substrate). Compositions comprising thephotoacid generators of Formula (I) are suitable for photo-inducedpolymerization, photo-induced crosslinking, photo-induced degradation,photo-induced deprotection, photo-induced color change or photo-inducedtransformation of functional groups or any combination of at least twoof them. Various exposure radiations can be used, including an exposurewith electromagnetic radiation having a wavelength of 200 to 500 nm,preferably in the range from 300 to 450 nm, more preferably in the rangefrom 350 to 440 nm, even more preferably at 365 nm (i-line), 436 nm(g-line) or 405 nm (h-line), wherein an electromagnetic radiation with awavelength of 365 nm is particularly preferred.

The photoresist compositions according to the present disclosurecomprise as component (ii) one or more photoresist polymers orcopolymers, which may be soluble or insoluble in a developer solution.The photoresist compositions according to the present disclosure may befor positive tone or negative tone composition. In the case of apositive tone composition the solubility of component (ii) is increasedupon reaction with the acid released from the compound according to thepresent disclosure. In this case, photoresist polymers or copolymerswith acid labile groups are used as component (ii) which are insolublein aqueous base solution, but which in the presence of the acid arecatalytically de-protected such that they become soluble in solution. Inthe case of a negative tone composition, the solubility of component(ii) is decreased upon reaction with the acid released from the compoundaccording to the present disclosure. In this case, photoresist polymersor copolymers are used as component (ii) which are soluble in thedeveloper solution, but are cross-linked in the presence of the acidsuch that they become insoluble in an aqueous base solution. Thus,photoresist polymers or copolymers are capable of being imparted with analtered solubility in a developer solution in the presence of an acid.Preferably the developer solution is an aqueous solution, morepreferably it is an aqueous base solution.

Examples of photoresist polymers that may be used as component (ii) in apositive tone composition include without limitation, aromatic polymers,such as homopolymers or copolymers of hydroxystyrene protected with anacid labile group; acrylates, such as for example, poly(meth)acrylateswith at least one unit containing a pendant alicyclic group, and withthe acid labile group being pendant from the polymer backbone and/orfrom the aclicyclic group, cycloolefin polymers, cycloolefin maleicanhydride copolymers, cycloolefin vinyl ether copolymers, siloxanes;silsesquioxanes, carbosilanes; and oligomers, including polyhedraloligomeric silsesquioxanes, carbohydrates, and other cage compounds. Theforegoing polymers or oligomers are appropriately functionalized withaqueous base soluble groups, acid-labile groups, polar functionalities,and silicon containing groups as needed.

Examples of copolymers that may be used as component (ii) in thepositive tone compositions of the present disclosure include withoutlimitation poly(p-hydroxystyrene)-methyl adamantyl methacrylate(PHS-MAdMA), poly(p-hydroxystyrene)-2-ethyl-2-adamantyl methacrylate(PHS-EAdMA), poly(p-hydroxystyrene)-2-ethyl-2-cyclopentyl methacrylate(PHS-ECpMA), poly(p-hydroxy-styrene)-2-methyl-2-cyclopentyl methacrylate(PHS-MCpMA) or PHS-EVE.

Preferably, the at least one component (ii) in a positive tonecomposition is a poly(hydroxystyrene)-resin in which at least a part ofthe hydroxy groups is substituted by protective groups. Preferredprotective groups are selected from the group consisting of atert-butoxycarbonyloxy group, a tert-butyloxy group, atert-amyloxycarbonyloxy group and an acetal group. Furthermore suitableas component ii) are all the polymers and copolymers which in paragraphs[0068] to [0114] of EP 1 586 570 A1 are described as “acid-dissociablegroup-containing resin.” The disclosure of EP 1 586 570 A1 with respectto these resins is incorporated herein by reference a forms a part ofthe present disclosure.

Preferred negative tone compositions comprise a mixture of materialsthat will cure, crosslink or harden upon exposure to acid. Preferrednegative acting compositions comprise, as component (ii), a polymerbinder such as a phenolic or non-aromatic polymer, a cross-linkercomponent as an additive (iv) and the photoacid generator componentaccording to the present disclosure as component (i). Suitable polymerbinders and cross-linkers for such negative tone photoresistcompositions and the use thereof have been disclosed in EP-A-0 164 248and U.S. Pat. No. 5,128,232. Preferred phenolic polymers for use ascomponent (ii) include novolaks and poly(vinylphenol)s. Novolak resinsare the thermoplastic condensation products of a phenol and an aldehyde.Examples of suitable phenols for condensation with an aldehyde,especially formaldehyde, for the formation of novolak resins includephenol, m-cresol, o-cresol, p-cresol, 2,4-xylenol, 2,5-xylenol,3,4-xylenol, 3,5-xylenol and thymol. An acid catalyzed condensationreaction results in the formation of a suitable novolak resin which mayvary in molecular weight from about 500 to 100,000 Daltons. Polyvinylphenol resins are thermoplastic polymers that may be formed by blockpolymerization, emulsion polymerization or solution polymerization ofthe corresponding monomers in the presence of a cationic catalyst.Vinylphenols useful for the production of polyvinyl phenol resins may beprepared, for example, by hydrolysis of commercially available coumarinor substituted coumarins, followed by decarboxylation of the resultinghydroxy cinnamic acids. Useful vinylphenols may also be prepared bydehydration of the corresponding hydroxy alkyl phenols or bydecarboxylation of hydroxy cinnamic acids resulting from the reaction ofsubstituted or non-substituted hydroxybenzaldehydes with malonic acid.Preferred polyvinyl phenol resins prepared from such vinylphenols have amolecular weight range of from about 2,000 to about 60,000 daltons.Preferred cross-linkers for use as component (iv) include amine-basedmaterials, including melamine, glycolurils, benzoguanamine-basedmaterials and urea-based materials. Melamine-formaldehyde polymers areoften particularly suitable. Such cross-linkers are commerciallyavailable, e.g., the melamine polymers, glycoluril polymers, urea-basedpolymer and benzoguanamine polymers, such as those sold by Cytec undertrade names Cymel™ 301, 303, 1170, 1171, 1172, 1123 and 1125 and Beetle™60, 65 and 80.

As component (iii) the composition according to the present disclosurecomprises at least one organic solvent. The organic solvent may be anysolvent capable of dissolving the component (ii) and the component (i)to generate a uniform solution, and one or more solvents selected fromknown materials used as the solvents for conventional chemicallyamplified resists can be used. Specific examples of the organic solventinclude ketones such as acetone, methyl ethyl ketone, cyclohexanone,methyl isoamyl ketone and 2-heptanone, water, polyhydric alcohols andderivatives thereof such as ethylene glycol, ethylene glycolmonoacetate, diethylene glycol, diethylene glycol monoacetate, propyleneglycol, propylene glycol monoacetate, dipropylene glycol, or themonomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether ormonophenyl ether of dipropylene glycol monoacetate, cyclic ethers suchas dioxane, and esters such as methyl lactate, ethyl lactate (EL),methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethylpyruvate, methyl methoxypropionate, and ethyl ethoxypropionate. Theseorganic solvents can be used alone, or as a mixed solvent containing twoor more different solvents. Particularly preferred organic solvents(iii) are selected from the group consisting of a ketone, an ether andester.

Furthermore, the composition according to the present disclosure mayalso, optionally, comprise at least one additive being different fromcomponents (i), (ii) and (iii). For example, other optional additivesinclude actinic and contrast dyes, anti-striation agents, plasticizers,speed enhancers, sensitizers, crosslinkers, monomers, polymers, binders,stabilizers, absorbers, fillers etc. Such optional additives typicallywill be in minor concentration in a photoresist composition except forfillers, binders, polymers, monomers and dyes which may be in relativelylarge concentrations such as, e.g., in amounts of from 5 to 80 percentby weight of the total weight of a resist's dry components.

One additive typically employed in photoresist compositions according tothe present disclosure is a basic quencher. The basic quencher is forpurposes of neutralizing acid generated in the surface region of theunderlying photoresist layer by stray light which reaches what areintended to be unexposed (dark) regions of the photoresist layer. Thisallows for improvement in depth of focus in the defocus area andexposure latitude by controlling unwanted deprotection reaction in theunexposed areas. As a result, irregularities in the profile, forexample, necking and T-topping, in formed resist patterns can beminimized or avoided.

To allow for effective interaction between the basic quencher and theacid generated in the dark areas of the underlying photoresist layer,the basic quencher should be of a non-surfactant-type. That is, thebasic quencher should not be of a type that migrates to the top surfaceof the overcoat layer due, for example, to a low surface free energyrelative to other components of the overcoat composition. In such acase, the basic quencher would not be appreciably at the photoresistlayer interface for interaction with the generated acid to prevent aciddeprotection. The basic quencher should therefore be of a type that ispresent at the overcoat layer/photoresist layer interface, whether beinguniformly dispersed through the overcoat layer or forming a graded orsegregated layer at the interface. Such a segregated layer can beachieved by selection of a basic quencher having a high surface freeenergy relative to other components of the overcoat composition.

Suitable basic quenchers include, for example: linear and cyclic amidesand derivatives thereof such as N,N-bis(2-hydroxyethyl)pivalamide,N,N-Diethylacetamide, N1,N1,N3,N3-tetrabutylmalonamide,1-methylazepan-2-one, 1-allylazepan-2-one and tert-butyl1,3-dihydroxy-2-(hydroxymethyl)propan-2-ylcarbamate; aromatic aminessuch as pyridine, and di-tert-butyl pyridine; aliphatic amines such astriisopropanolamine, n-tert-butyldiethanolamine,tris(2-acetoxy-ethyl)amine,2,2′,2″,2′″-(ethane-1,2-diylbis(azanetriyl))tetraethanol, and2-(dibutylamino)ethanol, 2,2′,2″-nitrilotriethanol; cyclic aliphaticamines such as 1-(tert-butoxycarbonyl)-4-hydroxypiperidine, tert-butyl1-pyrrolidinecarboxylate, tert-butyl 2-ethyl-1H-imidazole-1-carboxylate,di-tert-butyl piperazine-1,4-dicarboxylate and N(2-acetoxy-ethyl)morpholine. Of these basic quenchers,1-(tert-butoxycarbonyl)-4-hydroxypiperidine and triisopropanolamine arepreferred. While the content of the basic quencher will depend, forexample, on the content of the photoacid generator in the underlyingphotoresist layer, it is typically present in an amount of from 0.1 to 5wt %, preferably from 0.5 to 3 wt %, more preferably from 1 to 3 wt %,based on total solids of the overcoat composition.

Another concept is to attach a basic moiety to the PAG molecule. In thiscase the quencher is a part of the PAG and in close proximity to theacid formed upon irradiation. These compounds have a high sensitivitytowards electromagnetic radiation, in particular towards electromagneticradiation with a wavelength in the range of 200 to 500 nm, moreparticularly towards electromagnetic radiation with a wavelength of 365nm (i-line), and—at the same time—allows the production of a patternedstructure with a higher resolution, compared to the photoresistcompositions known from the prior art containing quenchers as additives.

The resin binder component of resists of the present disclosure aretypically used in an amount sufficient to render an exposed coatinglayer of the resist developable such as with an aqueous alkalinesolution. More particularly, a resin binder will suitably comprise 50 toabout 90 weight percent of total solids of the resist. The photoactivecomponent should be present in an amount sufficient to enable generationof a latent image in a coating layer of the resist. More specifically,the photoactive component will suitably be present in an amount of fromabout 1 to 40 weight percent of total solids of a resist. Typically,lesser amounts of the photoactive component will be suitable forchemically amplified resists.

According to a preferred embodiment, the compositions according to thepresent disclosure comprise:

-   -   (i) 0.05 to 15 wt. %, preferably 0.1 to 12.5 wt. % and most        preferably 1 to 10 wt. % of at least one photoacid generator        compound of Formula (I);    -   (ii) 5 to 50 wt. %, preferably 7.5 to 45 wt. % and most        preferably 10 to 40 wt. % of at least one photoresist polymer or        copolymer which may be base soluble or insoluble; and    -   (iv) 0 to 10 wt. %, preferably 0.01 to 7.5 wt. % and most        preferably 0.1 to 5 wt. % of the further additive, wherein the        reminder in the composition is the organic solvent (iii).

As in the compounds according to the present disclosure the functionalbasic group serving as a quencher for the acid group that is releasedupon exposure to electromagnetic radiation is a part of the photoacidgenerator compound, it is not necessary to add a separate basiccomponent as a quencher (as it is necessary in the photoresistcompositions known from the prior art). According to a preferredembodiment of the composition according to the present disclosure thiscomposition preferably comprises less than 5 wt. %, more preferably lessthan 1 wt. %, even more preferably less than 0.1 wt. %, and mostpreferably 0 wt. % of a basic compound being different from components(i) through (iv), such as hydroxides, carboxylates, amines, imines, andamides.

The photoresists of the present disclosure are generally preparedfollowing known procedures with the exception that a PAG of the presentdisclosure is substituted for prior photoactive compounds used in theformulation of such photoresists. For example, a resist of the presentdisclosure can be prepared as a coating composition by dissolving thecomponents of the photoresist in a suitable solvent such as, e.g., aglycol ether such as 2-methoxyethyl ether (diglyme), ethylene glycolmonomethyl ether, propylene glycol monomethyl ether; lactates such asethyl lactate or methyl lactate, with ethyl lactate being preferred;propionates, particularly methyl propionate and ethyl propionate; aCellosolve ester such as methyl Cellosolve acetate; an aromatichydrocarbon such toluene or xylene; or a ketone such as methylethylketone, cyclohexanone and 2-heptanone. Typically the solids content ofthe photoresist varies between 5 and 35 percent by weight of the totalweight of the photoresist composition.

The photoresist compositions of the present disclosure can be used inaccordance with known procedures. Though the photoresists of the presentdisclosure may be applied as a dry film, they are preferably applied ona substrate as a liquid coating composition, dried by heating to removesolvent preferably until the coating layer is tack free, exposed througha photomask to activating radiation, optionally post-exposure baked tocreate or enhance solubility differences between exposed and non-exposedregions of the resist coating layer, and then developed preferably withan aqueous alkaline developer to form a relief image. The substrate onwhich a resist of the present disclosure is applied and processedsuitably can be any substrate used in processes involving photoresistssuch as a microelectronic wafer. For example, the substrate can be asilicon, silicon dioxide or aluminum-aluminum oxide microelectronicwafer. Gallium arsenide, ceramic, quartz or copper substrates may alsobe employed. Substrates used for liquid crystal display and other flatpanel display applications are also suitably employed, e.g., glasssubstrates, indium tin oxide coated substrates and the like. A liquidcoating resist composition may be applied by any standard means such asspinning, dipping or roller coating. The exposure energy should besufficient to effectively activate the photoactive component of theradiation sensitive system to produce a patterned image in the resistcoating layer. Suitable exposure energies typically range from about 1to 300 mJ/cm². As discussed above, preferred exposure wavelengthsinclude sub-200 nm such as 193 nm. Suitable post-exposure baketemperatures are from about 50° C. or greater, more specifically fromabout 50 to 140° C. For an acid-hardening negative-acting resist, apost-development bake may be employed if desired at temperatures of fromabout 100 to 150° C. for several minutes or longer to further cure therelief image formed upon development. After development and anypost-development cure, the substrate surface bared by development maythen be selectively processed, for example chemically etching or platingsubstrate areas bared of photoresist in accordance with procedures knownin the art. Suitable etchants include a hydrofluoric acid etchingsolution and a plasma gas etch such as an oxygen plasma etch.

Composites

The present disclosure provides a process for producing a compositecomprising a substrate and a coating that is applied onto the substratein a patterned structure, the process comprising the steps of:

-   -   (a) applying a layer of the composition according to the present        disclosure onto the surface of the substrate and at least        partial removal of the organic solvent (iii);    -   (b) exposing selected areas of the layer to electromagnetic        radiation, thereby releasing an acid from the compound (i) in        the areas exposed to the electromagnetic radiation;    -   (c) optionally heating the layer to impart compound (ii) in the        areas in which the acid has been released with an altered        solubility in an aqueous solution; and    -   (d) optionally, at least partial removal of the layer.

In process step (a), a layer of the composition according to the presentdisclosure is applied onto the surface of the substrate followed by atleast partial removal of the organic solvent (iii).

Substrates may be any dimension and shape, and are preferably thoseuseful for photolithography, such as silicon, silicon dioxide,silicon-on-insulator (SOI), strained silicon, gallium arsenide, coatedsubstrates including those coated with silicon nitride, siliconoxynitride, titanium nitride, tantalum nitride, ultrathin gate oxidessuch as hafnium oxide, metal or metal coated substrates including thosecoated with titanium, tantalum, copper, aluminum, tungsten, alloysthereof, and combinations thereof. Preferably, the surfaces ofsubstrates herein include critical dimension layers to be patternedincluding, for example, one or more gate-level layers or other criticaldimension layer on the substrates for semiconductor manufacture. Suchsubstrates may preferably include silicon, SOI, strained silicon, andother such substrate materials, formed as circular wafers havingdimensions such as, for example, 20 cm, 30 cm, or larger in diameter, orother dimensions useful for wafer fabrication production.

Application of the composition according to the present disclosure ontothe substrate may be accomplished by any suitable method, including spincoating, curtain coating, spray coating, dip coating, doc-tor blading,or the like. Applying the layer of photoresist is preferablyaccomplished by spin-coating the photoresist using a coating track, inwhich the photoresist is dispensed on a spinning wafer. During the spincoating process, the wafer may be spun at a speed of up to 4,000 rpm,preferably from about 500 to 3,000 rpm, and more preferably 1,000 to2,500 rpm. The coated wafer is spun to remove the organic solvent (iii),and baked on a hot plate to remove residual solvent and free volume fromthe film to make it uniformly dense.

In process step (b), selected areas of the layer are exposed toelectromagnetic radiation, there-by releasing an acid from the compound(i) in the areas exposed to the electromagnetic radiation. As statedabove, various exposure radiations can be used, including an exposurewith electromagnetic radiation having a wavelength of 365 nm (i-line),436 nm (g-line) or 405 nm (h-line), wherein electromagnetic radiationhaving a wavelength of 365 nm is particularly preferred.

Such a pattern-wise exposure can be carried out using an exposure toolsuch as a stepper, in which the film is irradiated through a patternmask and thereby is exposed pattern-wise. The method preferably usesadvanced exposure tools generating activating radiation at wavelengthscapable of high resolution including extreme-ultraviolet (EUV) or e-beamradiation. It will be appreciated that exposure using the activatingradiation decomposes the component according to the present disclosurethat is contained in the photoresist layer in the exposed areas andgenerates acid and decomposition by-products, and that the acid theneffects a chemical change in the polymer compound (ii) (de-blocking theacid sensitive group to generate a base-soluble group, or alternatively,catalyzing a cross-linking reaction in the exposed areas). Theresolution of such exposure tools may be less than 30 nm. Alternativelythe irradiation may be performed using a beam of electromagneticradiation which is moved across the surface of the formulation wherebythe irradiated areas are selected by the movement of the beam.

In process step (c), the layer can optionally be is heated to impartcompound (ii) in the areas in which the acid has been released with analtered solubility in an aqueous solution. In this so called“post-exposure bake” the solubility differences between exposed andunexposed regions of the coating layer are created or enhanced.Typically post-exposure bake conditions include temperatures of about50° C. or greater, more specifically a temperature in the range of fromabout 50° C. to about 160° C. for 10 seconds to 30 minutes, preferablyfor 30 to 200 seconds. According to a particular embodiment of theprocess according to the present disclosure no heat treatment isperformed after process step (b) and before (d).

In process step (d) the layer is optionally at least partially removedwith an aqueous solution, preferably an aqueous base solution. This canbe accomplished by treating the exposed photoresist layer with asuitable developer capable of selectively removing the exposed portionsof the film (where the photoresist is positive tone) or removing theunexposed portions of the film (where the photoresist is negative tone).Preferably, the photoresist is positive tone based on a polymer havingacid sensitive (de-protectable) groups, and the developer is preferablya metal-ion free tetraalkylammonium hydroxide solution.

The composite made according to the present disclosure is characterizedin that it comprises a substrate and a coating applied on the surface ofthe substrate in a patterned structure, wherein the coating comprises acompound according to the present disclosure.

The use of the photoacid generator compounds of Formula (I) forphoto-induced polymerization, photo-induced cross-linking, photo-induceddegradation and photo-induced transformation of functional groups isalso within the scope of the present disclosure. The compound accordingto the present disclosure is particularly suitable for use in protectivecoatings, smart cards, 3D rapid prototyping or additive manufacturing,sacrificial coatings, adhesives, antireflective coatings, holograms,galvano- and plating masks, ion implantation masks, etch resists,chemical amplified resists, light sensing applications, PCB (printedcircuit board) patterning, MEMS fabrication, TFT layer pattering on flatpanel display, TFT layer pattering on flexible display, pixel patteringfor display, in color filters or black matrix for LCD, or semiconductorpatterning in packaging process and TSV related patterning onsemiconductor manufacturing protective coatings, smart cards, 3D rapidprototyping or additive manufacturing, sacrificial coatings, adhesives,antireflective coatings, holograms, galvano- and plating masks, ionimplantation masks, etch resists, chemical amplified resists, lightsensing applications or in color filters.

The following Examples are intended to illustrate the above disclosureand should not be construed as to narrow its scope. One skilled in theart will readily recognize that the Examples suggest many other ways inwhich the present disclosure could be practiced. It should be understoodthat many variations and modifications may be made while remainingwithin the scope of the present disclosure.

EXAMPLES

Examples 1, 2, 3, and 4 describe examples of synthesis of the sulfonatecompounds according to this invention.

Example 1: Synthesis of Compound I-1

To a 100 mL flask was charged vinyl admantane (5 g, 30.8 mmol),ICF₂CF₂OCF₂CF₂SO₂F (16.41 g, 38.5 mmol), 12 mL of water and 24 mL ofACN. The mixture was stirred under nitrogen for 10 min. To the mixturewas added a mixture of NaHCO₃ (1.59 g, 18.5 mmol) and a mixture ofsodium bisulfite and sodium metabisulfite (2.15 g). The reactiontemperature increased to 36° C. in 10 min. The temperature dropped to26° C. in 20 min. The mixture was then heated to 40° C. and kept at thesame temperature for 2 h. The mixture was cooled down to rt. Filtrationand washing with DI water afforded 16.0 g (yield: 88.3%) of compound I-1under air drying. ¹H NMR (300 MHz, CDCl₃) δ: 3.91 (dd, 1H), 2.95 (m,1H), 2.65 (m, 1H), 1.95 (br s, 3H), 1.40-1.70 (m, 12H). ¹³C NMR (75 MHz,CDCl₃) δ: 40.2, 37.1, 36.9, 36.5, 36.2, 28.5.

Example 2: Synthesis of Compound I-2

To a 250 mL flask was charged compound I-1 (17.8 g, 30.3 mmol) in 36 gof MTBE. The mixture was heated to 40° C., and tributyltin hydride (9.69g, 33.3 mmol) was added dropwise to the flask. After the addition, thereaction mixture was stirred at 40° C. overnight. The mixture was cooleddown to rt, and 20% of KF was added to the mixture. The mixture wasstirred at rt for several hours. The white precipitates were filtered,and the aqueous layer was separated. Removal of solvents under rotavapgave an oily residue which was purified by column chromatography. Thefinal compound I-2 was obtained in 7.1 g (yield: 51%) as a colorlessoil. ¹H NMR (300 MHz, CDCl₃) δ: 1.8-2.0 (br m, 5H), 1.61 (pq, 6H), 1.39(d, 6H), 1.2-1.3 (br m, 2H).

Example 3: Synthesis of Compound I-3

To a 100 mL flask was charged compound I-2 (10 g, 21.6 mmol) and NaOH(1.73 g, 43.3 mmol) in 50 mL of water. The mixture was heated at refluxovernight. The mixture was cooled down to rt. The water was removedunder rotavap to give 10.2 g (yield: 100%) of compound I-3 as a waxysolid. The compound I-3 was used in the subsequent reaction withoutfurther purification. ¹H NMR (300 MHz, DMSO) δ: 1.97-2.18 (br m, 2H),1.93 (br s, 3H), 1.63 (pq, 6H), 1.45 (d, 6H), 1.2-1.3 (br m, 2H).

Example 4: Synthesis of Compound A1

To a 50 mL flask was charged compound I-3 (2.0 g, 4.13 mmol) andtriphenylsulfonium bromide (1.42 g, 4.13 mmol) in 10 mL of water. Themixture was cooled down to rt. 10 mL of CH₂Cl₂ was added. The organiclayer was separated. Removal of solvents under rotavap gave 3.0 g of anoily residue. The oily residue was further purified by columnchromotagraphy to give 2.4 g (yield: 80%) of compound A1. ¹H NMR (300MHz, CDCl₃) δ: 7.6-7.8 (br m, 15H), 1.93-2.13 (br m, 2H), 1.87 (br s,3H), 1.59 (pq, 6H), 1.42 (d, 6H), 1.2-1.3 (br m, 2H). ¹³C NMR (75 MHz,CDCl₃) δ: 134.7, 131.7, 131.1, 124.3, 41.8, 36.9, 33.8, 31.4, 28.5, 24.1(t).

Compounds A2, A3, and A4 were similarly synthesized as examples 2, 3,and 4, respectively. Compound A2. ¹H NMR (300 MHz, CDCl₃) δ: 7.6-7.8 (brm, 14H), 1.93-2.13 (br m, 2H), 1.87 (br s, 3H), 1.62 (pq, 6H), 1.42 (d,6H), 1.34 (s, 9H), 1.2-1.3 (br m, 2H). ¹³C NMR (75 MHz, CDCl₃) δ: 159.1,134.5, 131.6, 131.4, 131.1, 128.8, 124.7, 120.5, 41.9, 36.9, 35.5, 33.8,31.4, 30.8, 28.5, 24.1 (t).

Compound A3. ¹H NMR (300 MHz, CDCl₃) δ: 7.58-7.78 (br m, 4H), 4.15 (m,2H), 3.64 (m, 2H), 3.55 (m, 4H), 1.93-2.13 (br m, 2H), 1.94 (br s, 3H),1.64 (pq, 6H), 1.42 (d, 6H), 1.31 (ps, 11H). ¹³C NMR (75 MHz, CDCl₃) δ:158.3, 129.6, 128.5, 122.4, 48.6, 41.9, 36.9, 35.3, 33.8, 31.4, 30.8,29.1, 28.5, 24.1 (t).

Compound A4. ¹H NMR (300 MHz, CDCl₃) δ: 7.4-7.8 (br m, 14H), 2.42 (s,3H), 1.93-2.13 (br m, 2H), 1.85 (br s, 3H), 1.62 (pq, 6H), 1.42 (d, 6H),1.2-1.3 (br m, 2H). ¹³C NMR (75 MHz, CDCl₃) δ: 146.4, 134.5, 132.4,131.6, 131.2, 130.9, 124.7, 120.5, 41.8, 36.9, 33.8, 31.4, 28.5, 24.1(t), 21.6.

Although illustrated and described above with reference to certainspecific embodiments and examples, the present disclosure isnevertheless not intended to be limited to the details shown. Rather,various modifications may be made in the details within the scope andrange of equivalents of the claims and without departing from the spiritof the present disclosure. It is expressly intended, for example, thatall ranges broadly recited in this document include within their scopeall narrower ranges which fall within the broader ranges. In addition,features of one embodiment may be incorporated into another embodiment.

What is claimed is:
 1. A sulfonic acid derivative compound representedby Formula (I):

wherein X is either H or —OH; and Y is a cation selected from eitherFormula A or B:

wherein R₁, R₂, and R₃ are each independently selected from the groupconsisting of a vinyl group, an allyl group, optionally substituted(C₁-C₂₀)alkyl group, and an optionally substituted (C₆-C₁₅)aralkylgroup, wherein R₁ and R₂ may be joined together along with the sulfur towhich they are attached to form a ring; and n is an integer from 1 to10.
 2. The sulfonic acid derivative compound of claim 1 wherein R¹, R²,and R³ are each independently an optionally substituted (C₆-C₁₅)aralkylgroup; and X is H.
 3. The sulfonic acid derivative compound of claim 1wherein R¹, R², and R³ are each independently an optionally substituted(C₆-C₁₅)aralkyl group; and X is —OH.
 4. The sulfonic acid derivativecompound of claim 1 wherein R¹ and R² are joined together along with thesulfur to which they are attached to form a ring; R³ is an optionallysubstituted (C₆-C₁₅)aralkyl group; and X is H.
 5. The sulfonic acidderivative compound of claim 1 wherein R¹ and R² are joined togetheralong with the sulfur to which they are attached to form a ring; R³ isan optionally substituted (C₆-C₁₅)aralkyl group; and X is —OH.
 6. Thesulfonic acid derivative compound of claim 1 selected from the groupconsisting of


7. The sulfonic acid derivative compound of claim 1 selected from thegroup consisting of


8. The sulfonic acid derivative compound of claim 1 selected from thegroup consisting of


9. A composition comprising: (i) at least one photoacid generatorcompound represented by Formula (I):

wherein X is either H or —OH; and Y is a cation selected from eitherFormula A or B:

wherein R₁, R₂, and R₃ are each independently selected from the groupconsisting of a vinyl group, an allyl group, optionally substituted(C₁-C₂₀)alkyl group, and an optionally substituted (C₆-C₁₅)aralkylgroup, wherein R₁ and R₂ may be joined together along with the sulfur towhich they are attached to form a ring; and n is an integer from 1 to10; (ii) at least one photoresist polymer or copolymer; (iii) an organicsolvent; and, optionally, (iv) an additive.
 10. The composition of claim9 wherein R¹, R², and R³ are each independently an optionallysubstituted (C₆-C₁₅)aralkyl group; and X is H.
 11. The composition ofclaim 9 wherein R¹, R², and R³ are each independently an optionallysubstituted (C₆-C₁₅)aralkyl group; and X is —OH.
 12. The composition ofclaim 9 wherein R¹ and R² are joined together along with the sulfur towhich they are attached to form a ring; R³ is an optionally substituted(C₆-C₁₅)aralkyl group; and X is H.
 13. The composition of claim 9wherein R¹ and R² are joined together along with the sulfur to whichthey are attached to form a ring; R³ is an optionally substituted(C₆-C₁₅)aralkyl group; and X is —OH.
 14. The composition of claim 9wherein R¹ and R² are each independently an optionally substituted(C₆-C₁₅)aralkyl group; and X is H.
 15. The composition of claim 9wherein R¹ and R² are each independently an optionally substituted(C₆-C₁₅)aralkyl group; and X is —OH.
 16. The composition of claim 9wherein the photoacid generator compound is selected from the groupconsisting of


17. The composition of claim 9 wherein the photoacid generator compoundis selected from the group consisting of


18. The composition of claim 9 wherein the photoacid generator compoundis selected from the group consisting of


19. The composition of claim 9 wherein the solvent is a glycol etherselected from the group consisting of 2-methoxyethyl ether (diglyme),ethylene glycol monomethyl ether, and propylene glycol monomethyl ether.20. The composition of claim 9 wherein the photoacid generator compoundis present in the composition at from about 1 to about 10 wt. %; the atleast one photoresist polymer or copolymer is present at from about 10to about 40 wt. %; and the remainder of the composition is the organicsolvent.